They believe they have built a 2-D covalent lattice from DNA oligomers. The flindamental unit of the construction is an antiparallel DNA double crossover molecule. These have been ligated into what they believe are about 1 ~ sheets. The first attempt to visualize this in the STEM found wall-to-wall proteinase K which had been used to stop the ligation. The second attempt found that the buffer control was rather dirty and consequently indistinguishable from the sample, though it was now free of extraneous protein. In both tries, some tantalizing areas could be found. Further work awaits additional purification.